laravel - Laravel 中访问模型关系的方式之间的差异

Question

访问模型关系时，以下有什么区别:

$post->comments

或者

$post->comments()

Answer 1

https://laravel.com/docs/5.1/eloquent-relationships#one-to-one

Once the relationship is defined, we may retrieve the related record using Eloquent's dynamic properties. Dynamic properties allow you to access relationship functions as if they were properties defined on the model

这个:

$posts = $user->posts;

实际上与此相同:

$posts = $user->posts()->get();

像这样使用它将导致获取关系实例:

$posts = $user->posts();

如果您想使用特定过滤器对其进行过滤，这会很方便，因为您现在可以对其应用查询生成器。